This is the 2nd test chamber I built, this time using an aquarium air stone as the air injection nozzle. The cloud of small bubbles it releases have a very different appearance when compared to the single larger bubble produced by the 1/8″ hose coupler nozzle.

I am getting more experienced using the acrylic welder to seal the bottom of the square extruded acrylic tube, but I still had some water weeping out the bottom when I tested it the first time. Adding more solvent fixed that issue.